The SUSE operating system must not forward Internet Protocol version 4 (IPv4) source-routed packets by default.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-217289 | SRG-OS-000480-GPOS-00227 | SLES-12-030370 | SV-217289r991589_rule | 2024-11-25 | 3 |
| Description |
|---|
| Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router. |
| ℹ️ Check |
|---|
| Verify the SUSE operating system does not accept IPv4 source-routed packets by default. Check the value of the default accept source route variable with the following command: # sysctl net.ipv4.conf.default.accept_source_route net.ipv4.conf.default.accept_source_route = 0 If the returned line does not have a value of "0" this is a finding. |
| ✔️ Fix |
|---|
| Configure the SUSE operating system to the required kernel parameter by adding the following line to "/etc/sysctl.conf" (or modify the line to have the required value): net.ipv4.conf.default.accept_source_route = 0 Run the following command to apply this value: # sysctl --system |